In decorating Christmas trees, it is difficult to arrange the lights in a relatively evenly dispersed manner on and between the tree limbs, even if all of the lights are in one continuous string, as is possible in three-wire systems such as those in which groups of series-connected low-voltage lights are connected in parallel, as disclosed in my co-pending application, Ser. No. 664,153, filed Oct. 24, 1984, or in two-wire systems using a transformer for reduction from the line voltage or using 110-120 volt bulbs.